Reservoir Having Wave Suppression Plate

ABSTRACT

A new and improved fluid storage reservoir that includes a wave suppression plate is provided. The wave suppression plate inhibits entraining air into fluid stored within the fluid storage reservoir by inhibiting wave formation and splashing of the fluid at the fluid-to-air interface within the fluid storage reservoir. The wave suppression plate is configured to inhibit mixing between a portion of fluid having a lower entrained amount of air below the wave suppression plate and a portion of fluid having a higher entrained amount of air above the wave suppression plate.

FIELD OF THE INVENTION

This invention generally relates to fluid storage reservoirs andparticularly fluid storage reservoirs configured to reduce theentrainment of air into the fluid stored within the fluid storagereservoirs.

BACKGROUND OF THE INVENTION

Many machines use fluids for operation. For instance, many tractors,trucks, or other types of mobile equipment often include hydraulicsystems for power and operating devices controlled by the machine.

Many of these machines will be exposed to large vibrations and impactsthat will cause the hydraulic fluid to splash and generate waves withinthe fluid storage reservoir. Many fluids, and particularly, hydraulicfluid will often entrain air at the surface of the fluid due to thesplashing and waves that are created due to the motion of the machine.The fluid with the entrained air will also then mix throughout the restof the fluid within the fluid storage reservoir.

Unfortunately, entrained air will often affect the performance andoperability of various components of the hydraulic system such ashydraulic pumps, cylinders or motors that use or otherwise process thehydraulic fluid.

The present invention provides improvements in fluid storage reservoirsto reduce the amount of air that is entrained and/or to inhibit mixingof the air entrained fluid with the rest of the fluid within the fluidstorage reservoir.

BRIEF SUMMARY OF THE INVENTION

Embodiments of the present invention relate to a new and improved fluidstorage reservoir. More particularly, embodiments of the presentinvention relate to a new and improved fluid storage reservoir thatincludes a wave suppression plate to inhibit entraining air into fluidstored within the fluid storage reservoir due to inhibiting waveformation and splashing of the fluid at the fluid-to-air interfacewithin the fluid storage reservoir. Additional benefits may be that thewave suppression plate prevents or otherwise inhibits mixing between aportion of fluid having a lower entrained amount of air below the wavesuppression plate and a portion of fluid having a higher entrainedamount of air above the wave suppression plate.

In one embodiment, a fluid storage reservoir including a tank and a wavesuppression plate is provided. The tank defines a fluid storage cavityin which fluid can be stored. The tank defines a bottom and a top. Thewave suppression plate is positioned between the bottom and the top andis offset from both the top and the bottom separating the fluid storagecavity into a top portion above the wave suppression plate and a bottomportion below the wave suppression plate. The wave suppression plate hasat least one opening that allows for fluid flow between the top andbottom portions.

In another embodiment, the tank includes an inlet and an outlet. Theinlet and outlet are positioned below the wave suppression plate and indirect fluid communication with the bottom portion of the fluid storagecavity.

In one embodiment, the at least one opening in the wave suppressionplate has a surface are of between about 50% and 125% of the entiresurface area of the outlet.

In one embodiment, the at least one opening includes a plurality ofopenings each having a cross-sectional area equal to a circle having adiameter of between about 0.1 inches and 0.256 inches.

In one embodiment, a predetermined volume of fluid is stored within thefluid storage cavity defining a fluid-to-air interface. The wavesuppression plate is positioned below the fluid-to-air interface. In analternative embodiment, the wave suppression plate is positioned abovethe fluid-to-air interface.

In one embodiment, the wave suppression plate is positioned between 40and 140 mm below the fluid-to-air interface.

In one embodiment, the plurality of openings are substantially equallyspaced.

In one embodiment, a secondary plate is offset from the wave suppressionplate and is positioned between the wave suppression plate and the topof the tank with the secondary plate positioned within the top portion.

In one embodiment, the secondary plate overlaps the at least one openingsuch that the secondary plate covers at least 75% of the surface are ofthe at least one opening.

In one embodiment, the secondary plate extends outward beyond theperiphery of the at least one opening by at least ¼ inch in a directiongenerally perpendicular to the direction of flow fluid through the atleast one opening.

In one embodiment, the secondary plate is spaced from the wavesuppression plate by a distance D1. The secondary plate extends outwardin a direction generally perpendicular to the flow of fluid through theat least one opening by at distance at least equal to distance D1.

In one embodiment, the at least one opening includes a plurality ofopenings.

In one embodiment, a method of inhibiting the entrainment of air withina fluid storage reservoir is provided. The method includes separating afluid storage cavity defined by an tank of a fluid storage reservoirinto a top portion and a bottom portion with a wave suppression platehaving at least one opening fluidly communicating the top portion withthe bottom portion.

In one method, the method includes redirecting the fluid flow after itflows from the bottom portion to the top portion using a secondary platespaced apart from the wave suppression plate. The secondary plate ispositioned within the top portion and between the wave suppression plateand a top of the tank.

In one method, the method includes drawing fluid out of the tank throughat least one outlet of the tank, the at least one opening having across-sectional area that is at least 50% the cross-sectional area ofthe at least one outlet.

In one method, the wave suppression plate is positioned between 140 mmabove and 140 mm below a fluid-to-air interface within the tank.

Other aspects, objectives and advantages of the invention will becomemore apparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention and,together with the description, serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a simplified perspective illustration of a fluid storagereservoir according to an embodiment of the invention;

FIG. 2 is a simplified cross-sectional illustration of the fluid storagereservoir of FIG. 1;

FIG. 3 is a partial cross-sectional illustration of a further embodimentof a fluid storage reservoir;

FIGS. 4 and 5 are additional partial cross-sectional illustrations ofthe embodiment of FIG. 3; and

FIG. 6 is a partial cross-sectional illustration of a further embodimentof a fluid storage reservoir.

While the invention will be described in connection with certainpreferred embodiments, there is no intent to limit it to thoseembodiments. On the contrary, the intent is to cover all alternatives,modifications and equivalents as included within the spirit and scope ofthe invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a simplified illustration of an embodiment of a fluid storagereservoir 100 according to the teachings of the present invention. Thefluid storage reservoir 100 is configured to store a fluid for use by adownstream system. In a particular embodiment, the fluid storagereservoir 100 is configured to be a fluid storage reservoir 100 forstoring hydraulic fluid.

With additional reference to FIG. 2, the fluid storage reservoir 100includes a tank 102 that defines a fluid storage cavity 104 in whichfluid can be stored. The tank 102 includes a top 106 and a bottom 108that is vertically spaced from the top 108. The illustrated tank isgenerally prismatic and includes sidewall 110 that extends generallybetween the top 106 and bottom 108 and surrounds, at least in part, thefluid storage cavity 104. In some embodiments, the tank could bespherical or have a bottom or top that could be dome or bowl shaped suchthat dome or spherical shape generally provides the sides, top and/orbottom of the tank, such designs will still be considered to have a top,a bottom and sides. In a preferred embodiment, the tank 102 is generallyformed from a pair of U-shaped wrapper portions that are coupledtogether to form and enclose the fluid storage cavity 104.

In the illustrated embodiment, the fluid storage reservoir 100 includesa fluid inlet 112 and a fluid outlet 114. The fluid inlet 112 and fluidoutlet 114 allow the fluid storage reservoir 100 to be connected to anexternal system, such as for example a hydraulic system or fuel system.Typically, fluid will be drawn from the fluid outlet 114 and passedthrough the system. Fluid returning to the fluid storage reservoir 100will typically enter through the inlet 112 during operation. While notshown, the fluid storage reservoir 100 could include other inlet andoutlet ports for filling or draining the fluid storage reservoir 100 atinitial setup or at maintenance intervals. Additional fluid inlets andfluid outlets may exist in any configuration of size, quantity, orlocation.

The fluid storage reservoir 100 includes a wave suppression arrangementin the form of wave suppression baffle illustrated as wave suppressionplate 120 positioned horizontally between the bottom 108 and the top106. The wave suppression plate 120 is vertically offset from both thetop 106 and the bottom 108. The wave suppression plate 120 separates thefluid storage cavity 104 into a top portion 122 above the wavesuppression plate 120 and a bottom portion 124 below the wavesuppression plate 120.

The wave suppression plate 120 includes a plurality of openings 126extending therethrough that allows for fluid flow between the top andbottom portions 122, 124. However, the inclusion of the openings 126inhibits easy mixing of the fluid within the top and bottom portions122, 124. The wave suppression plate 120 acts as a false top and reducesthe overall exposure of the entire volume of fluid to the fluid-to-airinterface 130 (shown schematically), which is the surface where thefluid meets the air stored within the fluid storage reservoir 100.

Ideally, a fluid storage reservoir would have no air stored therein soas to entirely avoid the possibility of entraining air within the fluidstored therein. However, due to, among other things, fluid usage, fluidleakage, imprecise filling and fluid expansion and contraction, fluidstorage reservoirs will almost always have some air therein. The wavesuppression plate 120 limits the amount of wave action and splashingaction within the fluid storage reservoir 100 so as to minimize theamount of air that is entrained into the fluid stored within the fluidstorage reservoir. The wave suppression plate 120 also limits the amountof mixing of the fluid within the tank such that the fluid above thewave suppression plate 120 exposed to the fluid-to-air interface doesnot mix as readily with the fluid below the wave suppression plate 120.Thus, the wave suppression plate allows for the fluid storage reservoir100 to be slightly larger than the exact necessary volume of fluidwithin the system so as to compensate for the changes in volume of fluidwithin the system while limiting the adverse effects of air entrainmentdue to the volume of air stored within the fluid storage reservoir.

Preferably, the openings 126 are sized to allow for fluid flow betweenthe top and bottom portions 122, 124, but inhibit significant mixingbetween the two portions and also act to prevent significant motion orsplashing within the bottom portion 124.

Due to this arrangement, the inlet 112 and outlet 114 are illustrated indirect fluid communication with the bottom portion 124 below the wavesuppression plate 120 so that the fluid that is drawn from the fluidstorage reservoir is, preferably, the fluid that has the least amount ofentrained air.

In this embodiment, it is preferred that the openings be small enoughto, at least partially, inhibit easy mixing between the two portions ofthe fluid storage cavity 104. In one embodiment, each opening has across-sectional area equal to a circle having a diameter of betweenabout 0.1 inches and 0.256 inches and is preferably about 0.16 inches.In some embodiments, the combined cross-sectional area of the openings126 is no less than 50% the combined cross-sectional area of all outletports (also referred to as suction ports). Preferably, the combinedcross-sectional area of the openings 126 is no more than 125% thecombined cross-sectional area of all outlet ports.

Preferably, the wave suppression plate 120 is positioned between 40 and140 mm above or below, but more preferably below, the fluid-to-airinterface 130 when the fluid storage reservoir 100 and fluid therein areat rest, such as at initial filling of fluid into the system.Additionally, the plurality of openings 126 are preferably substantiallyequally spaced.

The wave suppression plate 120 is preferably positioned such that nomore than 20% of the fluid volume is above the wave suppression plate120 within the top portion 120, more preferably, no more than 15%, andeven more preferably no more than 10%. Similarly, the wave suppressionplate 120 is preferably positioned such that there is a gap between thefluid-to-air interface and the bottom of the plate 120 that is less than20% of amount of volume of fluid within the tank 102, more preferably,no more than 15%, and even more preferably no more than 10%.

FIG. 3 illustrates a further embodiment of a fluid reservoir 200according to an embodiment of the present invention. This embodimentincludes a wave suppression arrangement 219 that includes a wavesuppression plate 220 and a secondary plate 221.

In this embodiment, the wave suppression plate 220 includes a pair ofenlarged openings 226 configured to allow fluid to transition betweentop and bottom portions 222, 224 of the fluid storage cavity 204.

The secondary plate 221 is spaced away from the wave suppression plate220 and is positioned between the top 206 and the wave suppression plate220. Preferably, the spacing D1 between the wave suppression plate 220and the secondary plate 221 is such that the fluid that passes from thebottom portion 224 to the top portion 222 of the fluid storage cavity204 is directed horizontally outward toward the sidewalls 210 of thestorage tank 202, as illustrated by arrows 223.

In one embodiment, D1 is no greater than 3 inches, preferably D1 is nogreater than 2 inches and even more preferably, D1 is no greater than 1inch. Further, D1 is preferably sufficiently large to preventunnecessary back pressure within the bottom portion 224 of the fluidstorage cavity 204. For instance, D1 is configured to prevent fluid tofluidly communicate through openings 226 into the remainder of topportion 222. Preferably, D1 is at least ⅛ inch, more preferably at least¼ inch.

In some embodiments, both wave suppression plate 220 and secondary plate221 are mounted such that both components are below the fluid-to-airinterface when the system is filled and the fluid is at rest, such as atinitial fluid filling of the system. In some embodiments, bothcomponents are positioned above the fluid-to-air interface when thefluid is at rest. In other embodiments, the wave suppression plate 220is located below the fluid-to-air interface and the secondary plate 22is above the fluid-to-air interface when fluid is at rest. Typically,when this is measured when the fluid is also at a standard temperatureof between about 50 and 80 degrees Fahrenheit.

In this embodiment, the secondary plate 221 extends entirely between twoopposed sidewalls 210 of the fluid tank 204. The two edges 225 of theplate 221 adjacent sides 210 attach the plate 221 to the sidewalls 210.The two edges 227 of secondary plate 221 that extend between edges 225are spaced away from adjacent sides 210 to allow fluid to flow into therest of top portion 224 of the fluid storage cavity 204. The secondaryplate 221 dampens the wave action. It that this change in directionhelps reduce the wave action within the tank 202 and helps reduceentrainment of air.

It is desired that at least 75% of the surface area of the openings 226are covered by the secondary plate 221. Preferably, the secondary plate221 completely overlaps all of the surface area of all of the openings226. Further, it is preferred that the openings 226 are covered by thesecondary plate 221 such that the secondary plate 221 extends outwardbeyond the periphery of the openings 226 by at least the distance D1.This region is illustrated in dashed lines in FIG. 3 and has a dimensionof D2. Preferably, D2 is greater than or equal to D1. In someembodiments, the distance (e.g. dimension D2) the secondary plate 221extends outward beyond the periphery of each opening is greater than ¼inch, more preferably ½ inch.

FIG. 6 illustrates a further embodiment of a fluid reservoir 300. Thisembodiment is similar to the embodiment of FIGS. 3-5. This embodimentfails to include the secondary plate of the prior embodiment. Instead,this embodiment only includes wave suppression plate 320 that definesopenings 326 that permit fluid communication between the top and bottomportions 322, 324 of the fluid storage cavity 304.

All references, including publications, patent applications, and patentscited herein are hereby incorporated by reference to the same extent asif each reference were individually and specifically indicated to beincorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

What is claimed is:
 1. A fluid storage reservoir comprising: a tankdefining a fluid storage cavity in which fluid can be stored, the tankdefining a bottom and a top; and a wave suppression plate positionedbetween the bottom and the top and offset from both the top and thebottom separating the fluid storage cavity into a top portion above thewave suppression plate and a bottom portion below the wave suppressionplate, the wave suppression plate having at least one opening thatallows for fluid flow between the top and bottom portions.
 2. The fluidstorage reservoir of claim 1 further comprising an inlet and an outlet,the inlet and outlet being positioned below the wave suppression plateand in direct fluid communication with the bottom portion of the fluidstorage cavity.
 3. The fluid storage reservoir of claim 2, wherein theat least one opening in the wave suppression plate has a surface are ofbetween about 50% and 125% of the entire surface area of the outlet. 4.The fluid storage reservoir of claim 1, wherein the at least one openingincludes a plurality of openings each having a cross-sectional areaequal to a circle having a diameter of between about 0.1 inches and0.256 inches.
 5. The fluid storage reservoir of claim 1, furthercomprising a predetermined volume of fluid stored within the fluidstorage cavity defining a fluid-to-air interface, the wave suppressionplate being positioned below the fluid-to-air interface.
 6. The fluidstorage reservoir of claim 5, wherein the wave suppression plate ispositioned between 40 and 140 mm below the fluid-to-air interface. 7.The fluid storage reservoir of claim 1, wherein the plurality ofopenings are substantially equally spaced.
 8. The fluid storagereservoir of claim 1, wherein each opening has a cross-sectional areaequal to a circle having a diameter of between about 0.1 inches and0.256 inches.
 9. The fluid storage reservoir of claim 1, furthercomprising a secondary plate offset from the wave suppression plate andpositioned between the wave suppression plate and the top of the tankwith the secondary plate positioned within the top portion.
 10. Thefluid storage reservoir of claim 9, wherein the secondary plate overlapsthe at least one opening such that the secondary plate covers at least75% of the surface are of the at least one opening.
 11. The fluidstorage reservoir of claim 10, wherein the secondary plate extendsoutward beyond the periphery of the at least one opening by at least ¼inch in a direction generally perpendicular to the direction of flowfluid through the at least one opening.
 12. The fluid storage reservoirof claim 10, wherein the secondary plate is spaced from the wavesuppression plate by a distance D1, wherein the secondary plate extendsoutward in a direction generally perpendicular to the flow of fluidthrough the at least one opening by at distance at least equal todistance D1.
 13. The fluid storage reservoir of claim 1, wherein the atleast one opening includes a plurality of openings.
 14. A method ofinhibiting the entrainment of air within a fluid storage reservoir, themethod comprising: separating a fluid storage cavity defined by an tankof a fluid storage reservoir into a top portion and a bottom portionwith a wave suppression plate having at least one opening fluidlycommunicating the top portion with the bottom portion.
 15. The method ofclaim 14, further comprising redirecting the fluid flow after it flowsfrom the bottom portion to the top portion using a secondary platespaced apart from the wave suppression plate, the secondary plate beingpositioned within the top portion and between the wave suppression plateand a top of the tank.
 16. The method of claim 14, further comprisingdrawing fluid out of the tank through at least one outlet of the tank,the at least one opening having a cross-sectional area that is at least50% the cross-sectional area of the at least one outlet.
 17. The methodof claim 14, wherein the wave suppression plate is positioned between140 mm above and 140 mm below a fluid-to-air interface within the tank.